Portable tapping machine



July 13 19126.

T. F. BRACKETT ET AL PORTABLE TAPPING MACHINE 1924 2 Sheets-Sheet 1 Filed Feb. 14 [BIZ IN l/E N TOR 222520 YFEKQCKE T7 A TTORNEYS July 13 1926.

2 Sheets-Sheet 2 lllugggggggwl T. F. BRACKETT ET AL PORTABLE TAPPING MACHINE Filed Feb. 14, 1924 w M m Mme n i A "n5 cm 5M lllllla m 5 M w 5 W m. 4. WJ M 6 A m Y Maw/Mg Ill Patented July 13, 1926.

UNITED STATES PATENT OFFICE.

TRACY F. BRACKETT ANDGEORGE H. BOYD, OF NEW YORK, N. Y.

PORTABLE TAPPING MACHINE.

Appligation filed February 14, 1924. Serial No. 692,863.

The present invention relates to portable drilling and tapping machines, and more particularly, aims to provide an improved type of machine for use in drilling and tapping pipes while the la'tte r are in service as conduit units in pipe lines conveying gases or liquids under pressure.

As is well known to those skilled in the art, it is often required that a. pipe unit of the kind and functioning as just mentioned, must be machined to providefat a selected point alongthe'pipe a tapped hole through the wall of the pipe, as for-making an extra take-off connection.

Such a pipe being filled with a gas or liquid under ressure when the drilling and tapping operation is to be performed, it is highly desirable, if not practically essential, that the drilling operation be performed, and immediately thereafter the tapping operation be performed, and by a single quickly attachable field-type or portable machine.

One of the important objects of the inventionis to provide means for permitting operation of such a portable drilling and tapping machine by power means availablein the field, such as power means operated by compressed. air, electricity, or gasoline; there preferably being employed as such power means a standard type of portable compressed air, electric, or gasoline drill.

Another object of the invention, then, is to incorporate means whereby said power means may be quickly and securely attached to or detached from the machine, so that when the power means is thus attached, it is effective to drive a gear train or the like, for giving the single drilling and tapping tool preferably provided its required rotary moven'ient, but so that, in'case of sudden break-down of the power means or failure of the power for operating the latter, such power means may be instantly removed. and

I said gear train or the like, immediately adapted for hand operatiomas by the application of a ratchet wrench for rotating the tool as above.

Another important objectof the invention is to provide a gear train or the like, and cooperant instrumentalities and auxiliary means the' latter preferably a lead screw coupled to or at will adapted to be coupled to the tool spindle, whereby, at least so far as theoperations of tapping or removing the t'appedportion of the tool are concerned, the gear train or the like will be effective to give the tool a movement of translation, simultaneously with and having a predetermined rate of advancerelative to the speed of rotation imparted to the tool by way of the gear train or the like.

As the invention is preferably embodied to attain all the foregoing and other objects of the invention, the machine includes rotating means for the tool including a gear train, one of the elements of which has a shaft which may be either hand or power driven as above; timing and driving means including said lead-screw for givingthetool a movement of translation having a predetermined rate of advance relative to the speed of rotation imparted tothe tool; manual means also including said lead-screw for giving the tool a. movement oi translation during rotation thereof; and means for at will coupling either said manual means or said timing and driving means to the tool rotating means.

A merely illustrative, and hence not the only possible, embodiment of the invention, is shown in the accompanying drawings in which I V Fig. l is what may be termed a side elevation of said embodiment with the latter applied and clamped in operating position when laterally offset from the pipe;

Fig. 2 is a horizontal section taken on line 2-2ofFig.l; I

Fig. 3 is a vertical sectional view taken perpendicular to the pipe axis with, however, certain of the parts of the machine means in elevation; I

Fig. 4C is a horizontal section taken on line il of Fig. 2;

Fig. 5 is a fragmentary vertical. sectional view showing more clearly and on a slightly enlarged scale the features of construction of certain of the parts disclosed in Fig. 3; and

Fig. 6 is a horizontal section taken on line 6-6 of Fig. 5.

Similar reference characters will be employed throughout the specification and.

drawings to designate corresponding parts. A machine of the character hereinabove indicated desirably includes a main body casting A for serving at once as a mount for a power means B and various rotating parts, and, in combination with an auxiliary casting A, as a mount for the journalling means -for said rotating parts and for gear 7 and having a squared upper end tion, and are shown and described herein merely for thepurpose of making clearly intelligible the disclosure of the invention here involved. 7

Referring partic'ularly'to Fig. 3 the rotating parts desirably include a driven spur gear 7: center spindle 8, the squared upper end of which carries gear 7 and the lower end of which carries the drill-and-tap instrumentality or tool E and a cylindrical rack or elongated pinion '9 meshing with m protruded beyond the wall 9 of casting s within which the upper end of pinion 9 is journalled. v

The parts just described comprise a geartrain whereby the portable, power means B of a standard type may have its rotary element B coupled as shown to the squared head 9 of pinion 9, and whereby, on actuating said means,the spindle 8 and its tool E will be spun. The means B, whichmay be an ordinary portable compressed-air, electric, or gasoline drill of which 'drill the socket inthe lower portion of member B may represent the bit-receiving chuck, is controlled in the usual way and by parts not shown for starting and stopping. Such drill is preferably detachably carried, as shown and as will be readily understood, by the fixture 10 forming a part of casting A; there being associated with said fixture a removable securing plate 11 and wing nuts 12 for clamping the plate and the drill to the fixture. Ordinarily, of course, the gear train for the tool E is power driven; yet by the arrangement just described, in case of a sudden break-down of the power means B during an emergency repair job in the field, such means may be removed and a ratchet wrench or the like applied to the squared upper end 9* of the pinion for hand operation of the gear train.

Casting A is closed at its bottom by a detachable floor-plate 15 provided with a depending split collar 15, as best shown in Fig. 2; so that the collar embracing the gland 14 which journals spindle 8 intermediate the ends of the latter may be drawn up tight, by means of bolt 16 and nut 17, around the uppermost cylindrical portion 18 of auxiliary casting A which constitutes with the nut 14 the box member for the packing of gland 14. Casting A is hollow in its lower portion to present a chamber 19, along the length of which chamber tool E may be advanced toward and through the pipe I), when spindle 8 is moved axially by means hereinafter described, during rotation of the spindle by the gear train. At its bottom, casting A fixedly carries a block having a bore 21 aligned with chamber 19 and forming an extension of said chamber; the. pipe contacting face of block 20 being interrupted by the lower end of bore 21 but otherwise arched to match the exterior curvature of pipe D. V

The means C for coacting with said block 20 in permitting quick yet secure attachn'ient of the machine to the pipe, includes the following elements: Loosely rotatable on casting A is a collar 22 having a pair of parallelly olfset arms 23 on opposite sides thereof. These arms carry at their upper outer portions transverse and aligned notches for cradling bar-type hangers 24 for a gripping chain 25. Each of these hangers is of a triangular cross section so as to be slightly rockably received in the. notches of the allotted pair. of arms 23. At a point along the lengthof' the bar hanger which will lie in the space between its supporting pair of arms 23, the bar hanger carries a depending hook 26 for taking a link of the chain 25.

In order to permit feeding of tool E downward for a drilling operation relative to pi 3e D during rotation of spindle 8 by the gear train, the following arrangements are provided. Gear 7 is so designed that its hub, a portion of which is comprised by a screwplug 7 provided merely for convenience in assembling the machine, is loose within a yoke 27, which, as shown mostclearly perhaps in Fig. 4, has one of its ends keyed in a channel guide 28 at one side of casting A, and has its other end, cut away to sleeve pinion 9 without contact, set in a channel guide 29 at the opposite side of casting A. These channel guides 28 and 29 extend parallelly from top to bottom of the main portion of casting A housing the gear train.

In order to take advantage of the features of construction just described and manually control'the feed of the tool E downward for the drilling operation, the following arrangements are made: Axially aligned with and above spindle 8 is a vertical lead-screw 30 which screw, as best shown in Fig. 5, is attached at its lower end by way of a machine-screw 31 and the hub-block 7 of gear 7 to said gear. Lead-screw 30 and spindle 8 have interposed therebetween a thrustbearing as shown at 32. Screw 30 works relative to a nut 33 fixed in the casting A; and such screw is provided at its top and outside the casting A with a handle 34, whereby the screw may be manually turned and, through the thrust bearing 32, the spindle 8 and the tool E may be moved axially.

When tool E is so moved manually, as toward the pipe during a drilling operation,

the coactant ratchet-clutch devices 35 and 36, one formed at the upper portion of hub block 7 and the other formed at the lower portion of a slidably adjustable collar 37 on lead-screw 30, are inefiectively spaced as shown in full lines in Fig. 3 and in broken lines in Fig. 5; that is to say, handle 34 may be utilized to turn the lead-screw as and when desired during continuous high speed rotation of spindle 8. These ratchet-clutch elements 85 and 36 are securely maintained inefiiectively spaced, for the operation just described, by setting a spring-retracted pullstud 38 carried by collar 37, in an upper recess 39 formed in screw as shown in Fig- 5; which engagement of the stud and recess is always made easy by virtue of the fact that the collar is feathered on the screw as indicated at 40.

In order, however, that the lead-screw 30 and consequently the spindle 8 and tool E may be fed at a rate predetermined relative to the speed of rotation of the spindle, as for insuring that the upper, threaded, or tap portion of tool E may follow through the hole just previously drilled by the lowermost conical drill-bit portion of said tool, immediately upon completion of the drilling of the hole, there is provided in addition to the ratchet-clutch elements and 36 and the stud 38, a second and lower recess 41 in screw 30 for taking the inner end of the stud when collar 37 is shifted from the broken line to the full line position in Fig. 5. It will be understood that with the collar thus moved and the parts arranged as shown in Fig. 5, the ratchet-clutch 3536 is set to couple lead-screw 30 and spindle 8 into one rotatory structure. The result of such coupling is that the lead-screw and spindle rotate as one unit and that the gear 7 and tool E are downwardly spirally fed in accordance with the pitch of the thread of the lead-screw and the speed of rotation of pinion 9. Also setting of the ratchet clutch as shown in Fig. 9 insures that when the hole in the pipe is drilled and tapped and the tool E is to be withdrawn, by a reverse rotation of the gear train, said tool may be withdrawn without any danger of injuring or stripping the threads of the hole.

The drill and tap are combined into one tool means E and the provisions just described are provided, for readily and at will, and without having to dismantle the ma chine or the operating mechanism in any way, coupling or uncoupling the screw 30 relative to the gear train drive,-for the reason that the machine of the present invention is usually if not always applied to a gas or liquid pipe line and the required hole must be drilled and tapped before th gas or liquid reaches the stufling-box nut 14 The operation of the machine when applied and clamped to a pipe D by the means C, should be obvious from the foregoing; but it will be understood that, first, with the ratchet-cluteh 3536 disposed as shown in Fig. 1 and ineffectively set relative to screw 730 and spindle 8, the power means B is opthe collar 37 is slid downward to interlock the ratchet-clutch elements 35 and 36, the pull stud now snapping into the recess 41 in the screw; next, power means B isstarted again and now the axial feed as well as the rotation of spindle 8 and tool E are both set up and maintained by the power means B, to start and complete the tapping operation; and finally, on reversing the direction of rotation of the gear train, the axial feed as well as the speed of rotation of the spindle and tool are likewise set up and maintained by said power means to start and complete the withdrawal of the entire tool from the pipe and without stripping the threads formed in the hole in the pipe.

As point-ed out near the beginning or" the specification, the parts designated by the reference letters C and E from no part of the invention of the present application, nor does the stuffing-box which journals the spindle 8.

I claim:

1. In a portable machine for drilling and tapping adapted to be driven by a portable power means, the combination with a support and drilling and tapping tool means thereon, of a pair of gears, one of which is adapted to be driven by said power means and the other of which has the tool means secured thereto, the second mentioned gear being mounted to slide on the support in the direction of drilling, a yoke mounted to slide in the direction of drilling to maintain said gears intermeshed at all times, a lead-screw, and a clutch for connecting the lead-screw and said second n'ientioned gear when desired.

2. In a portable machine for drilling and tapping adapted to be driven by a portable power means, the combination with a supand said second mentioned gear when desired, and a locking pin toprevent accidental engagement of the clutch.

3. In a portable tapping machine adapted to be driven by power means, the combination with a housing anda tapping tool, or a gear train in the housing, a lead-screw, a clutch for operatively connecting the leadscrew and tapping tool through the gear train, means for maintaining the gear elements of the train in mesh during operation of the machine While the clutch is operatively connected to the tapping tool, means for hand operation of the tapping tool in the event of the power means failing, and means for hand operation of the lead-screw irrespective of the operation of the means last mentioned.

TRACY F. BRACKET? GEORGE H. BOYD. 

